We have to repeat the same steps again as for invocation_expression to get:
post_decrement_expression
: (array_creation_expression
| literal
| simple_name
| parenthesized_expression
| predefined_type DOT IDENTIFIER type_argument_list?
| qualified_alias_member DOT IDENTIFIER type_argument_list?
| this_access
| base_access
| object_creation_expression
| delegate_creation_expression
| anonymous_object_creation_expression
| typeof_expression
| checked_expression
| unchecked_expression
| default_value_expression
| anonymous_method_expression
| sizeof_expression
) (DOT IDENTIFIER type_argument_list?
| OPEN_PARENS argument_list? CLOSE_PARENS
| OPEN_BRACKET (expression_list | expression) CLOSE_BRACKET
| OP_INC
| OP_PTR IDENTIFIER
| OP_DEC
)+
;
The second pass has to check that array_creation_expression may not be followed by OPEN_BRACKET. It has to be also checked that OP_DEC is the last matched sequence.